Perhaps one of the most common queries concerning data import into any geospatial software regards the correct plotting of coordinate values from spreadsheets. This post provides a checklist that hopefully will encourage the understanding of coordinate values, the implications of how they are managed and the relationship to coordinate reference systems Read more…
Geomatics World has published, in their September/October 2018 issue, an article, written by Simon Kettle, on how the European datum of 1950 came about and how it became the de facto standard after World War II. Read the article in Geomatics World magazine by following this link.
In a previous blog I mentioned how ArcGIS Pro did not have the functionality to create geodesic lines. Well there is an add-in available for that now and it can be used in ArcGIS Pro 1.4 – 2.0 as well as in ArcMap and ArcGIS Web AppBuilder. It is free Read more…
What are Geodesic distances? A geodesic line is the shortest path between two points on a curved surface, like the Earth. They are the analogue of a straight line on a plane surface or whose sectioning plane at all points along the line remains normal to the surface. It is a way of showing Read more…
What is a Vertical Datum? The Geodetic Glossary (2009) defines height as ‘distance, measured along a perpendicular, between a point and a reference surface’. This definition is concise and direct but leaves a vagueness concerning the reference surface. This reference surface is the Vertical Datum. A datum is required to reach accurate and reliable Read more…
I decided to look into some of the mathematics that makes it possible to calculate distances considering 3D space, for example, calculating distance on a sphere. The Earth is round but big so we can consider it flat for short distances. But, even though the circumference of the Earth is Read more…